1 /*-
2 * SPDX-License-Identifier: BSD-2-Clause
3 *
4 * Copyright (c) 2004-2011 David Schultz <das@FreeBSD.ORG>
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26 * SUCH DAMAGE.
27 */
28
29 #ifndef _FENV_H_
30 #error "This file is meant to be included only by <fenv.h>."
31 #endif
32
33 /*
34 * This file implements the functionality of <fenv.h> on platforms that
35 * lack an FPU and use softfloat in libc for floating point. To use it,
36 * you must write an <fenv.h> that provides the following:
37 *
38 * - a typedef for fenv_t, which may be an integer or struct type
39 * - a typedef for femode_t, which may be an integer or struct type
40 * - a typedef for fexcept_t (XXX This file assumes fexcept_t is a
41 * simple integer type containing the exception mask.)
42 * - definitions of FE_* constants for the five exceptions and four
43 * rounding modes in IEEE 754, as described in fenv(3)
44 * - a definition, and the corresponding external symbol, for FE_DFL_ENV
45 * - a definition, and the corresponding external symbol, for FE_DFL_MODE
46 * - a macro __set_env(env, flags, mask, rnd), which sets the given fenv_t
47 * from the exception flags, mask, and rounding mode
48 * - macros __env_flags(env), __env_mask(env), and __env_round(env), which
49 * extract fields from an fenv_t
50 * - a definition of __fenv_static
51 *
52 * If the architecture supports an optional FPU, it's recommended that you
53 * define fenv_t and fexcept_t to match the hardware ABI. Otherwise, it
54 * doesn't matter how you define them.
55 */
56
57 extern int __softfloat_float_exception_flags;
58 extern int __softfloat_float_exception_mask;
59 extern int __softfloat_float_rounding_mode;
60 void __softfloat_float_raise(int);
61
62 __fenv_static inline int
feclearexcept(int __excepts)63 feclearexcept(int __excepts)
64 {
65
66 __softfloat_float_exception_flags &= ~__excepts;
67 return (0);
68 }
69
70 __fenv_static inline int
fegetexceptflag(fexcept_t * __flagp,int __excepts)71 fegetexceptflag(fexcept_t *__flagp, int __excepts)
72 {
73
74 *__flagp = __softfloat_float_exception_flags & __excepts;
75 return (0);
76 }
77
78 __fenv_static inline int
fesetexceptflag(const fexcept_t * __flagp,int __excepts)79 fesetexceptflag(const fexcept_t *__flagp, int __excepts)
80 {
81
82 __softfloat_float_exception_flags &= ~__excepts;
83 __softfloat_float_exception_flags |= *__flagp & __excepts;
84 return (0);
85 }
86
87 __fenv_static inline int
feraiseexcept(int __excepts)88 feraiseexcept(int __excepts)
89 {
90
91 __softfloat_float_raise(__excepts);
92 return (0);
93 }
94
95 __fenv_static inline int
fetestexcept(int __excepts)96 fetestexcept(int __excepts)
97 {
98
99 return (__softfloat_float_exception_flags & __excepts);
100 }
101
102 __fenv_static inline int
fegetround(void)103 fegetround(void)
104 {
105
106 return (__softfloat_float_rounding_mode);
107 }
108
109 __fenv_static inline int
fesetround(int __round)110 fesetround(int __round)
111 {
112
113 __softfloat_float_rounding_mode = __round;
114 return (0);
115 }
116
117 __fenv_static inline int
__fegetmode_int(femode_t * __modep)118 __fegetmode_int(femode_t *__modep)
119 {
120
121 __set_env(*__modep, 0, __softfloat_float_exception_mask,
122 __softfloat_float_rounding_mode);
123 return (0);
124 }
125
126 __fenv_static inline int
__fesetmode_int(const femode_t * __modep)127 __fesetmode_int(const femode_t *__modep)
128 {
129
130 __softfloat_float_exception_mask = __env_mask(*__modep);
131 __softfloat_float_rounding_mode = __env_round(*__modep);
132 return (0);
133 }
134
135 __fenv_static inline int
fegetenv(fenv_t * __envp)136 fegetenv(fenv_t *__envp)
137 {
138
139 __set_env(*__envp, __softfloat_float_exception_flags,
140 __softfloat_float_exception_mask, __softfloat_float_rounding_mode);
141 return (0);
142 }
143
144 __fenv_static inline int
feholdexcept(fenv_t * __envp)145 feholdexcept(fenv_t *__envp)
146 {
147 fenv_t __env;
148
149 fegetenv(__envp);
150 __softfloat_float_exception_flags = 0;
151 __softfloat_float_exception_mask = 0;
152 return (0);
153 }
154
155 __fenv_static inline int
fesetenv(const fenv_t * __envp)156 fesetenv(const fenv_t *__envp)
157 {
158
159 __softfloat_float_exception_flags = __env_flags(*__envp);
160 __softfloat_float_exception_mask = __env_mask(*__envp);
161 __softfloat_float_rounding_mode = __env_round(*__envp);
162 return (0);
163 }
164
165 __fenv_static inline int
feupdateenv(const fenv_t * __envp)166 feupdateenv(const fenv_t *__envp)
167 {
168 int __oflags = __softfloat_float_exception_flags;
169
170 fesetenv(__envp);
171 feraiseexcept(__oflags);
172 return (0);
173 }
174
175 #if __BSD_VISIBLE
176
177 /* We currently provide no external definitions of the functions below. */
178
179 __fenv_static inline int
feenableexcept(int __mask)180 feenableexcept(int __mask)
181 {
182 int __omask = __softfloat_float_exception_mask;
183
184 __softfloat_float_exception_mask |= __mask;
185 return (__omask);
186 }
187
188 __fenv_static inline int
fedisableexcept(int __mask)189 fedisableexcept(int __mask)
190 {
191 int __omask = __softfloat_float_exception_mask;
192
193 __softfloat_float_exception_mask &= ~__mask;
194 return (__omask);
195 }
196
197 __fenv_static inline int
fegetexcept(void)198 fegetexcept(void)
199 {
200
201 return (__softfloat_float_exception_mask);
202 }
203
204 #endif /* __BSD_VISIBLE */
205